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CVE.org (no NVD analysis yet)· CNA curl

CVE-2026-86409: stale SigV4 headers sent unintended

Noroxi assessment

Priority: Monitor (action score 0/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.25% (FIRST EPSS).
  • Fixed version: curl (Alpine:v3.23) 8.23.0-r0; curl (Debian:14) 8.22.0-1; curl (openSUSE:Tumbleweed) 8.23.0-1.1.

Low priority for now. Upgrade to curl (Alpine:v3.23) 8.23.0-r0; curl (Debian:14) 8.22.0-1; curl (openSUSE:Tumbleweed) 8.23.0-1.1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

Setting `CURLOPT_AWS_SIGV4` to NULL but does not disable SigV4 authentication, contrary to expectations and documentation. A subsequent transfer on the same handle still sends an `Authorization: AWS4-HMAC-SHA256` header to whatever URL isset next, leaking state information.

—No exploit Fix available
Published
Oct 20, 2026
Updated
Oct 22, 2026
EPSS
0.2% · 17th percentile

Report tools

JSON

Action score

0

Monitor

Low priority for now.

CVSS
0 / 40 · —
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

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  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

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  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (curl). Independent of NVD's CPE analysis and usually ahead of it.

  • curl curl

    • 8.21.0 and later · up to and including 8.21.0affected · semver
    • 8.20.0 and later · up to and including 8.20.0affected · semver
    • 8.19.0 and later · up to and including 8.19.0affected · semver
    • 8.18.0 and later · up to and including 8.18.0affected · semver
    • 8.17.0 and later · up to and including 8.17.0affected · semver
    • 8.16.0 and later · up to and including 8.16.0affected · semver
    • 8.15.0 and later · up to and including 8.15.0affected · semver
    • 8.14.1 and later · up to and including 8.14.1affected · semver
    • 8.14.0 and later · up to and including 8.14.0affected · semver
    • 8.13.0 and later · up to and including 8.13.0affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Alpine:v3.23curlbefore 8.23.0-r08.23.0-r0
Debian:12curlfrom 0—
Debian:14curlbefore 8.22.0-18.22.0-1
openSUSE:Tumbleweedcurlbefore 8.23.0-1.18.23.0-1.1
Red Hat:hummingbird:1curlbefore 0:8.23.0-0.1.hum10:8.23.0-0.1.hum1
Red Hat:hummingbird:1libcurlbefore 0:8.23.0-0.1.hum10:8.23.0-0.1.hum1
Red Hat:hummingbird:1libcurl-develbefore 0:8.23.0-0.1.hum10:8.23.0-0.1.hum1
Red Hat:hummingbird:1libcurl-minimalbefore 0:8.23.0-0.1.hum10:8.23.0-0.1.hum1

Same product

curl: all records

Other highest-scoring records for the same primary product.

  • CVE-2012-0036curl and libcurl 7.2x before 7.24.0 do not properly consider special characters during extraction of a pathname from a URL, which allows rem
    35Monitor
  • CVE-2026-92392HTTP/2 upload Use-After-Free
    32Monitor
  • CVE-2005-3185Stack-based buffer overflow in the ntlm_output function in http-ntlm.c for (1) wget 1.10, (2) curl 7.13.2, and (3) libcurl 7.13.2, and other
    32Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2009-0037Mar 4, 2009 · The redirect implementation in curl and libcurl 5.11 through 7.19.3, when CURLOPT_FOLLOWLOCATION is enabled, accepts arbitrary Location valu
    30Monitor
  • ← EarlierCVE-2010-3842Oct 27, 2010 · Absolute path traversal vulnerability in curl 7.20.0 through 7.21.1, when the --remote-header-name or -J option is used, allows remote serve
    24Monitor
  • Later →CVE-2026-86410Oct 20, 2026 · redirect to SFTP or SCP bypasses host verification
    0Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
alpine:curl8.23.0-r0 · Alpine:v3.23Package registry (OSV)
debian:curl8.22.0-1 · Debian:14Package registry (OSV)
opensuse:curl8.23.0-1.1 · openSUSE:TumbleweedPackage registry (OSV)
red hat:curl0:8.23.0-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:libcurl0:8.23.0-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:libcurl-devel0:8.23.0-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:libcurl-minimal0:8.23.0-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. Published
  2. Fix recordedsame day
  3. TodayOct 26, 2026+6 d
EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-864130 days apartNegotiate credentials sent to redirected origin
    0Monitor
  • CVE-2026-864140 days apartleaking host credentials to HTTP proxy
    0Monitor
  • CVE-2026-864150 days apartauto client cert connection reuse mixup
    0Monitor
  • CVE-2026-878610 days apartcross-origin reuse of a Negotiate connection
    0Monitor
  • CVE-2026-878620 days apartHSTS cache import drops longer-lived child
    0Monitor
  • CVE-2026-878630 days apartHSTS response erases persisted entries
    0Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

The product’s vendor appears in a public program. Matched by name; verify the scope text in the program.

Technical details

No CVSS vector for this record, so attack conditions can't be derived.

Weakness class (CWE)

CWE-201 · Insertion of Sensitive Information Into Sent Data

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓
  2. Exploit maturity— → none

For records you follow, these changes also arrive as notifications. →

References

Show all references (2 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records